I have an April 2011 built X3, 35 Xi. From the time I took delivery of the car, I felt that the cabin was not quiet and I could hear the road/wind noise.

I came across a post in this forum, which said this was a know issue in X3s manufactured before June of 2011.

It is apparently due to a leaky mirror gasket. I took the car to the dealer yesterday and I was told that there was a bulleting on this. But they did not have any parts becasuse it is such a common occurence.